Servomotors for industrial valves are electromechanical systems acting on the valve of an industrial fluid circuit so as, depending on the pressure encountered in the valve, to act to close it, open it or keep it in its current state.
Servomotors are suitable for different types of valves, and may therefore be quarter-revolution or multi-revolution servomotors. They are often used under demanding environmental conditions, and must therefore often be tight, impermeable to dust, and able to withstand cold or heat. Indeed, servomotors for industrial valves are found in harsh environments such as refineries, nuclear power plants, or treatment plants.
Electric servomotors comprise an electric motor and a kinematic chain for transmitting power from the motor to an actuating element of the valve, by suitably downshifting the torque supplied by the motor.
They also have sensors for monitoring the state of the valve and a local control unit for controlling the motor and the kinematic chain. The latter may receive commands from a command unit outside the servomotor placed elsewhere in the industrial installation, and able to be tasked with commanding several servomotors placed on different valves of the installation.
To send these commands, as well as the electrical power necessary for the operation of the motor, as well as, in the reverse direction, the signals coming from the internal sensors, an electrical connection with multiple contacts, independent of one another, is present on a wall of one of the enclosures of the servomotor. Traditionally, each time the servomotor is disassembled, then reassembled on a given valve, the electrical connection with multiple contacts should be disassembled, which involves many screwing and unscrewing operations of screws on eye wires. This is time-consuming and tedious, and sometimes a source of errors. The tightness is in particular ensured using cable glands, which must be tightened.